Methods and apparatus for downstream dissociation of gases

Abstract

A method and apparatus for activating and dissociating gases involves generating an activated gas with a plasma located in a chamber. A downstream gas input is positioned relative to an output of the chamber to enable the activated gas to facilitate dissociation of a downstream gas introduced by the gas input, wherein the dissociated downstream gas does not substantially interact with an interior surface of the chamber.

1 . A system for exciting gases comprising; 
 a remote plasma source for generating a plasma region in a chamber, wherein the plasma generates an activated gas;    an injection source for introducing a downstream gas to interact with the activated gas outside the plasma region, wherein the activated gas facilitates excitation of the downstream gas, and wherein the excited downstream gas does not substantially interact with an interior surface of the chamber; and    a feature for providing a gap between an output flange of the chamber and the injection source.    
   
   
       2 . The system of  claim 1  wherein the gap is a long, narrow gap that reduces the transport of excited gases to a seal located between the output flange of the chamber and a portion of the system.  
   
   
       3 . The system of  claim 1  wherein the gap has a length of at least 2.54 mm.  
   
   
       4 . The system of  claim 1  wherein the gap has a length of between about 5.08 mm and 50.8 mm.  
   
   
       5 . The system of  claim 1  wherein the gap has a width of between about 0.0025 mm and 1.524 mm.  
   
   
       6 . The system of  claim 1  wherein the gap has a width of between about 0.025 mm and 0.508 mm.  
   
   
       7 . The system of  claim 1  wherein the gap has a length to width ratio of about 1.66.  
   
   
       8 . The system of  claim 1  wherein the gap has a length to width ratio of about 3.33.  
   
   
       9 . The system of  claim 1  wherein the length of the gap is between about 2.54 mm and about 50.8 mm and the width of the gap is between about 0.0025 mm and about 1.524 mm.  
   
   
       10 . The system of  claim 1  wherein the feature is annular shaped.  
   
   
       11 . The system of  claim 1  wherein the feature is a flange.  
   
   
       12 . The system of  claim 1  wherein the feature is a spring seal.  
   
   
       13 . The system of  claim 1  wherein the feature can be compressed and extended within its elastic deformation range.  
   
   
       14 . The system of  claim 1  wherein the feature comprises aluminum, sapphire or a nitride.  
   
   
       15 . The system of  claim 1  wherein the feature separates the output flange of the chamber from a body of the injection source.  
   
   
       16 . The system of  claim 1  wherein the feature limits rubbing between the output flange and the body of the injection source.  
   
   
       17 . The system of  claim 1 , comprising a sealing mechanism between the output flange and the injection source.  
   
   
       18 . The system of  claim 1  wherein the sealing mechanism comprises an o-ring.  
   
   
       19 . The system of  claim 1  wherein the sealing mechanism comprises a spring seal.  
   
   
       20 . A method for exciting gases comprising; 
 generating an activated gas with a plasma in a chamber;    positioning a downstream gas input relative to an output of the chamber to enable the activated gas to facilitate dissociation of a downstream gas introduced by the gas input, wherein the dissociated downstream gas does not substantially interact with an interior surface of the chamber; and    positioning a feature for providing a gap between an output flange of the chamber and a body comprising the downstream gas input.    
   
   
       21 . The method of  claim 20  wherein the gap is a long, narrow gap that reduces the transport of excited gases to a seal located between the output flange of the chamber and a portion of the system.  
   
   
       22 . The method of  claim 20  wherein the feature is annular shaped.  
   
   
       23 . The method of  claim 20  wherein the feature is a flange.  
   
   
       24 . The method of  claim 20  wherein the feature is a spring seal.  
   
   
       25 . The method of  claim 20  wherein the feature can be compressed and extended within its elastic deformation range.  
   
   
       26 . The method of  claim 20  wherein the feature separates the output flange of the chamber from a body of the injection source.  
   
   
       27 . The method of  claim 20  wherein the feature limits rubbing between the output flange and the body of the injection source.  
   
   
       28 . The method of  claim 20 , comprising creating a vacuum seal between the output flange and the injection source.  
   
   
       29 . A method for dissociating gases comprising; 
 generating an activated gas with a plasma in a chamber;    positioning a downstream gas input relative to an output of the chamber to enable the activated gas to facilitate dissociation of a downstream gas introduced by the gas input, wherein the dissociated downstream gas does not substantially interact with an interior surface of the chamber; and    positioning a feature for providing a gap between an output flange of the chamber and a body comprising the downstream gas input.    
   
   
       30 . A system for exciting gases comprising; 
 a remote plasma source for generating a plasma region in a chamber, wherein the plasma generates an activated gas; and    an injection source for introducing a downstream gas to interact with the activated gas outside the plasma region, wherein the activated gas facilitates excitation of the downstream gas, and wherein the excited downstream gas does not substantially interact with an interior surface of the chamber.    
   
   
       31 . The system of  claim 30  wherein excitation of the downstream gas comprises dissociating the downstream gas.  
   
   
       32 . The system of  claim 30 , comprising a barrier located at an output of the chamber to reduce erosion of or deposition onto the chamber.  
   
   
       33 . The system of  claim 32  wherein the barrier is located at least partially within the chamber.  
   
   
       34 . The system of  claim 32  wherein the barrier is located at least partially within an output passage of the chamber.  
   
   
       35 . The system of  claim 30 , comprising a barrier located within an output passage of the chamber.  
   
   
       36 . The system of  claim 30  wherein the chamber comprises quartz.  
   
   
       37 . The system of  claim 36  wherein the chamber is a toroidal-shaped chamber.  
   
   
       38 . The system of  claim 30  wherein the plasma source is a toroidal plasma source.  
   
   
       39 . The system of  claim 30  comprising a mixer to mix downstream gas and activated gas.  
   
   
       40 . The system of  claim 39  wherein the mixer comprises a static flow mixer, a helical mixer, blades, or a stacked cylinder mixer.  
   
   
       41 . The system of  claim 30  comprising a purge gas input.  
   
   
       42 . The system of  claim 41  wherein the purge gas input is located between an outlet of the chamber and an input of the injection source.